Incandescent lamp.



G. I. DODSON.

vINGANDESCENT LAMP. APPLIOATION FILED 11.21.1909.

Patented Allg. 9, 1910.

Zafifffjjw (uber/nui o lie 4 To all 'whom it may concernf UNITED sTA'riis PATENT OFFICE.

i4 CHARLES I. DODSON, 0F PITTSBURG, KANSAS, ASSIGNOR OF ONE-#FOURTH T0 HARRY S. CLARK, ONE-EIGHTH TO ARCHIBALD T. CHEATHAM. AND ONE-EIGHTI-I T0 JOSEPH FLETCHER,- OF PITTSBURG, KANSAS.

INCANDESCENT LAMP.

acacia.

Patented Aug. a, 1ero,

Application filed April 9, 1909. Serial No. 488,864.

Be it known that I, (J1-Manns l. DonsoN, acitizen of the United States, residing at Pittsburg, in the county of Crawford and State of Kansas, have invented a new and useful Incandescent Lamp, ot' which the following is a specification.

This invention has reference to improvements in incandescent electric lampsand is designed to produce an incandescent lamp the filament of which has a plurality of external connections so arranged that should the filament or portions of the filament in use burn out or become broken through some cause, the lamp may still be as serviceable as ever by removing one of the external circuit terminals and exposing |another leading to the unbroken portion of the lament. l

The invention will be best understood from a consideration of the following detail description taken in connection with the accompanying drawings forming a part oit' this specification in which drawings,

Figure '.l is a side `elevation of an incandescent lamp constructed in accordance with the present invention. F ig. 2 is a central longitudinal section of the base endof the lamp ona larger scale than shown in Fig. l, and Fig. 3 is a detail View showing another arrangement of the'ilament.

Referring to the drawings there is shown a lamp l of ordnaryconstruction so far as ,l the general external appearance is concerned;

4wires will be found suiicient.

and this lamp is provided with a filament 2 so coupled up 4as to represent two or more use ful lilaments each giving the desired standard candle-power in light. The lamp is provided with the usual screw base 3, in the drawings shown as of the ordinary Edison type but it will be understood that any other suitable type of base may be used. Since the lamp 1n its general structure may be such as 1s ordinarily employed no detail description of the generalstructure is deemed necessary. Y

- In the particular construction shown the lamp is provided with three leading-in wires Il, 5 and 6, but more leading-in wires may be used it deemed necessary. Under ordinary circumstances three of these leading-in One of the leadin -in wires say the central wire 4 is carrie to the screw shell of the base as is Ilcustomary in lamps ot' this type. In the the latter may be easily particular structlue shown the leading-in conductor 4 is connected to the central portion-of the lilament 2 while the ends of this filament are connected to the two conductors 5 and 6 and each of these conductors is carried thronvh the base 3 and is there secured t0 a plate or 8 as the case may be, the conductor 5 being shown as connected to the plate 7 and the conductor 6 to the plate 8. lit is the usual custom in lamps of this type to carry the one terminal of the lamcnt to a leading-in conductor to a plate concentric with the longitudinal central axis of the lamp, and this plate is made a Jermanent partof the lamp base. With a amp constructed in accordance with the present invention one oi these plates, say the plate 7 may be made practically permanent with the base while the other plate, say the plate 8 is made so as to be readily detached when desired. These two plates are made to lie in parallel relation under ordinary circumstances with a sheet 9 of insulating material separating them, so that the two plates 7 and 8 are maintained out of electrical contact. The plate 8 may be connected to the conductor 6 through a narrow terminal band l0 rso that when desired'the plate 8 may be.

bent to one side and because of the attenuated character of the connecting band 10, broken olf and the plate 8 thrown away after whichI the insulating lamina 9 may be removed thus expos` ing the plate 7.

Let it be assumed that the' lamp in ordinary use is screwed into the usual Vsocket then a circuit is established between the walls of the socket and the screw member of the base and from thence through the leading-in wire or conductor 4 to the filament and through the latter to the conductor 6 and thence by way of the neck l0 to the plate 8 andto the other terminal of the base. When the circuit is completed b the lamp switch or 'otherwise then the portlon of the lilament included between the conductor 6 and the conductor 4 will glow in the usual manner while the other portion of the filament, that is the, portion between therconductors 5 and 4 is out of circuit and thereforeinert for light giving purposes. Now let it be assumed that either because of use or from accidental causes the portion ofthe filament 2 between the conductors 4. and 6 becomes burned out or otherwise broken. Under such conditions a lamp as ordinarily constructed becomes useless and must either be thrown away or renewed at considerable expense. When such a condition arises with the lam shown in the drawings then the plate 8 1s simply bentout of' the way and moved back and forth a few times until the neck 10 becomes broken when the late may be thrown away and the disk 9 of insulating material may be removed. Now the lamp may be replaced in the-socket and the plate 7 will come in contactwith the correspondin terminal inthe socket 'and the circuit wil be established at this point; The circuit will find a path through the leading-in conductor 4 to the 'unbroken or unburned portion of the filament thence out through the leading-in conductor 5 to the plate 7. -The new portion of the filament having been unused will under ordinary conditions have as long life as the first portion of the filament and therefore the lamp asa whole has ltwice the life of an ordinary two-terminal lamp.

In external appearance the lamp has all the characteristics of an ordinary amp but wil-l give twice the service of an ordinary lamp without requiring any modification whatsoever iii the ordinary lamp socket, while the only difference between the ordinary lamp and the improved lamp is in the addition of an extra central terminal for the base which may be quickly removed at will and without the aid of tools of any kind.

The extra cost of applying the improveL ment to lam s in the course of manufacture is so inconsi erable as to be nearly neglivible and no change in the ordinary parts o? the lamp is necessary. Furthermore, the imroved lamp requires no change whatsoever 1n the lamp receiving socket or other members, and any person however unskilled may readily renew the operative condition of the lamp should the filament being used become burned out.

In Fig. l the filament is shown in the form of a double loop, with each loop constituting an individual light giving member. In Fig.' 3 the filament is shown as formed of two double loops instead of two single loops as in Fig'. 1. This will illustrate the use of the invention for different forms of filaments and may be taken as indicative of any type of filament desired..

While the lamp is shown as provided with two terminal plates 7 and 8 only it will be understood that more such plates properly insulated one from the other and a correspondingly greater number of active filament sections may be employed as may be found expedient. Of course it will be understood that distinct filaments may he used instead 0f filament. sections and so by the expression a plurality of filaments, or a multiple filament will be understood as meaning either a single filament connected up to the leading-in conductors to constitute a number of active Sections, or a plurality of distinct filaments coupled up in like manner.

What is claimed is 1. An incandescent lamp having a plurality of filaments and an equal number of like external terminals for the filaments insulated one from the other and all in the longitudinal axis of the lamp. f 2. An incandescent lamp having a plurality of filaments and an equal number of like external terminals for the filaments in the form of plates insulated one from the other and one `parallel with the other and all in the longitudinal axis of the lamp.

3. An incandescent lamp having a plurality of filaments and an equal number of like external terminals for 'the filaments in the form of plates insulated one from the other and parallel one with the other and all in the longitudinal axis of the lamp, an outer plate and adjacent insulation being readily removable to expose the plate thereunder.

4. An incandescent lamp having a plurality of filaments and an equal number of like external terminals for the filaments in' the form of plates one overlying and insulated from the other, the overlying plate and adjacent insulation being readily removable to expose the underlying plate.

5. An incandescent lamp having a plurality of filaments and an equal number of like external terminals for the filalnents, one terminal overlying and being insulated from the other and readily' removable together with the insulating material to expose the underlying terminal.

In testimony that I claim the foregoing as my own, I have hereto affixed my signature in the presence of two witnesses.

CHARLES i. DoDsoN.

Witnesses:

G. C. MOORE, O. T. Cnorrniz. 

